From the mid-13th century, the relationship between Alfonso X of Castile and his mistress Mayor Guillen de Guzman gave rise to a veritable feminine dynasty, beginning with their daughter Beatriz - later Queen of Portugal through her marriage - and continued through the latter's daughter, Princess Blanca of Portugal, the grand-daughter of Mayor Guillen, well until the 1320s. In this time, the ladies belonging to this illegitimate line of Alfonso X's descent kept a special commitment to the Castilian crown, as well as to certain interests of piety and power related to this king. The continuity along this Alfonsine line of the important noble family of Guzman stands as a showcase of the public relevance of women set in a high environment.